Date: Sat, 01 Jan 2011 17:59:10 +0100 From: =?ISO-8859-1?Q?Beat_G=E4tzi?= <beat@chruetertee.ch> To: Kostik Belousov <kostikbel@gmail.com> Cc: Alexander Best <arundel@freebsd.org>, current@freebsd.org Subject: Re: Suddenly slow lstat syscalls on CURRENT from Juli Message-ID: <4D1F5D5E.8030602@chruetertee.ch> In-Reply-To: <20110101164649.GY90883@deviant.kiev.zoral.com.ua> References: <4D1F1AE8.5040704@chruetertee.ch> <20110101151008.GA7762@freebsd.org> <4D1F4A48.6080604@chruetertee.ch> <20110101154537.GW90883@deviant.kiev.zoral.com.ua> <4D1F4FB8.3030303@chruetertee.ch> <20110101161254.GX90883@deviant.kiev.zoral.com.ua> <4D1F5992.8030309@chruetertee.ch> <20110101164649.GY90883@deviant.kiev.zoral.com.ua>
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On 01.01.2011 17:46, Kostik Belousov wrote: > On Sat, Jan 01, 2011 at 05:42:58PM +0100, Beat G?tzi wrote: >> On 01.01.2011 17:12, Kostik Belousov wrote: >>> On Sat, Jan 01, 2011 at 05:00:56PM +0100, Beat G?tzi wrote: >>>> On 01.01.2011 16:45, Kostik Belousov wrote: >>>>> Check the output of sysctl kern.maxvnodes and vfs.numvnodes. I suspect >>>>> they are quite close or equial. If yes, consider increasing maxvnodes. >>>>> Another workaround, if you have huge nested directories hierarhy, is >>>>> to set vfs.vlru_allow_cache_src to 1. >>>> >>>> Thanks for the hint. kern.maxvnodes and vfs.numvnodes were equal: >>>> # sysctl kern.maxvnodes vfs.numvnodes >>>> kern.maxvnodes: 100000 >>>> vfs.numvnodes: 100765 >>>> >>>> I've increased kern.maxvnodes and the problem was gone until >>>> vfs.numvnodes reached the value of kern.maxvnodes again: >>>> # sysctl kern.maxvnodes vfs.numvnodes >>>> kern.maxvnodes: 150000 >>>> vfs.numvnodes: 150109 >>> The processes should be stuck in "vlruwk" state, that can be >>> checked with ps or '^T' on the terminal. >> >> Yes, there are various processes in "vlruwk" state, >> >>>> As the directory structure is quite huge on this server I've set >>>> vfs.vlru_allow_cache_src to one now. >>> Did it helped ? >> >> No, it doesn't looks like setting vfs.vlru_allow_cache_src helped. The >> problem was gone when I increased kern.maxvnodes until vfs.numvnodes >> reached that level. I've stopped all running deamons but numvnodes >> doesn't decrease. > Stopping the daemons would not decrease the count of cached vnodes. > What you can do is to call unmount on the filesystems. Supposedly, the > filesystems are busy and unmount shall fail, but it will force freed > the vnodes that are unused by any process. That freed around 1500 vnodes. At the moment the vfs.numvnodes doesn't increase rapidly and the server is usable. I will keep an eye it to see if I run into the same problem again. Thanks for your help! Beat
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